Genetic diversity and molecular phylogeny of Anaplasma marginale studied longitudinally under natural transmission conditions in Rio de Janeiro, Brazil

摘要: Anaplasma marginale is the most prevalent tick-borne pathogen in cattle tropical and subtropical regions of world. Major Surface Protein 1a (MSP1a) has been found to be a stable genetic marker for identifying A. isolates within geographical regions. It conserved during infection transmission pathogen. The aim present longitudinal study was determine occurrences diversity associated with high prevalence under natural conditions. Twenty calves were evaluated every 3 months first year life. Rickettsemia levels due marginale, measured as number msp1αcopies/ml blood positive calves, ranged from 2.06×10(3) 4.36×10(12). numbers MSP1a tandem repeats among 6. predominant msp1α microsatellite E, another repeat that presented genotype G. Nineteen different circulating animals. 4-63-27 (27.5%), 78-24(2)-25-31 (n=21.6%) τ-10(2)-15 (n=17.6%) ones commonly observed. Twenty-two resulted new sequences amino acid changes, shown this study. Thirty time Brazil. Glycine, glutamate, serine alanine acids at position 20. During study, 80% (16/20) animals infected by more than one genotype. Three born infected, 4-63-27, τ-10(2)-15, thus indicating occurrence transplacental transmission. In phylogenetic analysis, 19 cattle, which suggested many variation occurring.